plugin/dot_layout: use GVDLL instead of _WIN32 to enable dllexport storage-class...

Towards https://gitlab.com/graphviz/graphviz/-/issues/2173.

diff --git a/plugin/dot_layout/gvplugin_dot_layout.c b/plugin/dot_layout/gvplugin_dot_layout.c
index fda227c82ad03daf8c3875538d982d9db920a0e7..168e8e3990cbbd0a4545169d2b7beb4e443ccebe 100644 (file)
--- a/plugin/dot_layout/gvplugin_dot_layout.c
+++ b/plugin/dot_layout/gvplugin_dot_layout.c
@@ -18,7 +18,7 @@ static gvplugin_api_t apis[] = {
 };
 
 
-#ifdef _WIN32
+#ifdef GVDLL
 #define GVPLUGIN_DOT_LAYOUT_API __declspec(dllexport)
 #else
 #define GVPLUGIN_DOT_LAYOUT_API